Turbo-compressor casing



E. H. SHERBONDY.

TURBO COMPRESSGR CASING.

APPLICATION FILED AUG.1.1918.

1,400,323. I lamented Dec. 13, 1921.

WITNESS BY I Armin/Er UNITED STATES.

PATENT OFFICE.

near. E. smaonnr, or cnnvnnmn, oino.

.rums'o-comranssoa casino.

- Patented Dec. 13, 1921.

Application filed August 1, 1918. Serial No. 247,848.

shaft therewith. The turbine is adapted to be operated by thevexhaustgases from an internal combustion engme, it in turn operating thecompressor wheel of the usual centrifugal type to compress air forcombustion in the engines, or for other purposes. The turbo-compressorcasing is of that general type disclosed in my co-pending case SerialNo. 224,892, filed Mar. 26, 1918.

The high temperature of the exhaust gases will obviously cause theturbine casing to become very hot. It .has been found that with a casingmade entirely ofmetal, parts of the casing, especially the back-plate ofthe turbine casing are distorted by the high temperature and alsoby thepressure of the exhaust gases against it, as they leave the turbinebuckets. The back plate near the turbine buckets is subject to a greaterconcentration of gas, as it leaves the buckets, which causes this partto be more highly heated than the parts farther out and this unequalheating also causes distortion of the plate.

It is an object of this invention to provide aback plate for the turbinecasing of material that will be substantially unaffected by the heatofthe exhaust gases.

To this end this back plate is made of refractory material. Asrefractory material, there may be used:

Graphite, carborundum, alundum, fused silica, crucible clay. An otherdesired refractory material, may 0 course be used.

Other objects and advantages will appearas the description proceeds.

In the drawings illustrating an embodiment of my invention, Figure 1 isa side view in section of a turbine easing,'showing my invention and Fi2 is an end view of the back plate used, sfiown broken away and on asmaller scale.

Referring now to the drawings, the turbocompressor unit, is shown asconsisting of a turbine wheel 1 and a compressor wheel 2, both mountedon a common shaft 3, which in turn is mounted in bearings 4 and 5.

The wheel 2, is of an ordinary centrifugal type and has associatedtherewith a front casing element 6 and a fear casing element 7, thetwobeing assembled to inclose the wheel 2 and to define a chamber 8, forthe compressed air. The air enters the wheel 2, through the intake mouth9. i

The turbine casing comprises a main casing element 10, which is annularand shaped substantially like a shallow dish-pan. This casing isprovided with one or more inlet ports 11 and one or more exhaust ports12, for the inlet and exhaust respectively of the gases that operate theturbine.

Positioned within the casing element 10, there is an annulardiaphragm-13, which defines inlet and exhaust chambers 14 and 15respectively. The inner part of. the diaphragm 13, terminates justadjacent the buckets 16 of the turbine, in order to guide the as to saidbuckets.

T e turbine casing is .completed by the annular backing plate 17,located on the other side of the turbine buckets from the diaphragm 13.This plate 17 is positioned in the path of the gases leaving the buckets16 and guide these gases into the exhaust chamber 15, from whence theyescape to the atmosphere through the exhaust port 12. This backing plate17, it has been found, when made of sheet metal is subject to distortionby the heat and to dislocation by the pressure of the exhaust gasesagainst it, as they leave the turbine buckets.

On account of the small clearances used in such a structure, thisdistortion has caused bindin of the parts and leakage of gas. Thisdlstortion is due to the unequal heating of the back plate, it being ata much higher temperature toward the inner part,adjacent the bucket 16,than at the outer part, toward the peri hery.

In or er to overcome these disadvantages,

this back plate is made of a material which mission of heat to theadjacent compressor casing 7. This plate 17 is annular and is held inposition by being clamped against an annular rib 18, which rib is inturn supported by lugs 22 cast integral with thecasing 7 and said rib.Plate 17 is held against this rib by an asbestos washer 19' and a steelwasher 19, which in turn are clamped by bolt 20, between an edge 21 ofthe turbine casing and the rib 18. For convenience in assembling, plate17, may be made in sections.

While I have illustrated a possible embodiment of my invention, itshould be understood that the invention may be carried out in otherways, as defined within the scope of the following claims.

I claim:

1. In combination with a gas engine turbine, a peripherally supportedbafiie in the path of the exhaust from said turbine, said bafiie beingfree to flex along its body without transmitting the distortionsubstantially to the support of said bafiie.

2. In combination with a gas engine turbine, a peripherally supportedrefractory baflle in the path of the exhaust from said turbine, saidbaffle being free to flex along its body without transmitting thedistortion substantially to the support of said battle.

3. In combination with the exhaust casing of a gas engine turbine, adefiectingbafile in the path otthe exhaust gases of said turbinesupported in said casing along the edge of said bafile, said bafllebeing free to flex along its body without transmitting the distortionsubstantially to the support for the edge of said baflle.

1. In combination with the exhaust casing of a gas engine turbine, arefractory deflecting baflle in the path of the exhaust gases of saidturbine supported in said cas-.

ing along the edge of said balfle, said bafiie being free to flex alongits body without transmitting the distortion substantially to thesupport for the edge of said baflie.

5. A turbine casing comprising an exhaust chamber for hot gases having abaflle as one wall thereof, a deflection chamber contiguous to and forsaid bafile wall, and a compressor means contiguous to said deflectionchamber operated by said turbine.

In testimony whereof I! a fiix my signature.

EARL H. SHERBONDY.

